Secondhand 20 Hi Cold Rolling Mill
Technical Introduction
This meticulously restored used cold rolling mill represents the pinnacle of thin-gauge metal processing technology. Engineered as a 20 hi cold rolling mill, this second hand 20 hi reversible crm delivers exceptional precision for high-value applications across aerospace, automotive, and electronics sectors. Originally designed for industrial-scale production, its comprehensive refurbishment ensures OEM-equivalent performance at 50-70% capital cost savings while processing 25-ton coils at speeds up to 360 m/min.
Core Specifications
| Parameter | Value |
|---|---|
| Roll Configuration | 20-Hi cluster design |
| Max Material Width | 1,270 mm |
| Thickness Range | Input: 2.0-3.0 mm → Output: 0.20-2.0 mm |
| Tolerance | ±0.01 mm (transverse/longitudinal) |
| Max Coil Weight | 25 tons |
| Coil Dimensions | ID: Ø610 mm / OD: Ø2,000 mm |
| Roll Force | 10,000 kN |
| Tension Capacity | 32 tons |
| Rolling Speed | 300 m/min (operational) / 360 m/min (max) |
Roll Stack Specifications
| Roll Type | Diameter | Material | Quantity |
|---|---|---|---|
| Work Rolls | Ø80 mm | Cr12Mo1V1 | 20 |
| 1st Intermediate | Ø105 mm | Cr12Mo1V1 | 8 |
| 2nd Intermediate | Ø169 mm | 9Cr2Mo/V | 4 |
| Backup Bearings | Ø300 mm | Alloy steel | 64 |
Revamped Drive & Control Systems
Power Transmission:
Dual 900KW DC motors (660V, 360-950 rpm)
Fully digital current-speed dual closed-loop control
Adjustable magnetic field circuits
Precision Systems:
Hydraulic four-cylinder roll chock balancing
Drive engagement on both sides of 2nd intermediate rolls
Maximum mill opening: 35 mm
Refurbishment Certification
Restored to exceed original performance:
Roll Stack: Laser realignment (<0.005mm/m tolerance)
Bearings: SKF/FAG premium series replacement
Control Systems: Modernized tension feedback loops
Structural Integrity: Magnetic particle testing on chocks
Validation: 120-hour test run with 0.20mm stainless steel
Technical Advantages
1. Unmatched Precision
Maintains ±0.01mm tolerance at 0.20mm thickness
20-roll configuration distributes stress, eliminating edge waves
Hydraulic balancing ensures uniform roll gap geometry
2. Material Versatility
| Material | Min. Thickness | Tolerance Class |
|---|---|---|
| 400 Series SS | 0.20 mm | Aerospace Grade |
| Silicon Steel | 0.25 mm | EIW 400 Compliance |
| Low-Alloy Steel | 0.30 mm | ISO 9444 Standard |
3. Productivity Features
Reversible Operation: Single-pass reductions ≤85%
High-Speed Threading: 0.2-0.5 m/s strip engagement
Rapid Changeovers: <45 minutes for alloy transitions
Industry Applications
| Sector | Critical Use Cases |
|---|---|
| Electronics | EMI shielding foils (0.20mm ±0.008mm) |
| Automotive | EV battery current collectors |
| Energy | Transformer core laminations |
| Aerospace | Engine shim stock (0.25mm SS321) |
Operational Economics
| Metric | This Mill | New Equivalent |
|---|---|---|
| Capital Investment | $1.8M | $5.2M+ |
| ROI Period | 18 months | 48+ months |
| Energy Consumption | 1,800 kW (peak) | 2,500 kW (peak) |
| Tooling Cost | $22,000/roll set | $68,000/roll set |
Service Ecosystem
Pre-Commissioning:
Material trials (1,000 kg provided)
Plant integration simulation studies
After-Sales Assurance:
24-month warranty on drive systems
Remote diagnostics via secure VPN
Lifetime spare parts availability
On-site training: Levels 1-3 certification
